Project Summary Physical activity rates decrease across the lifespan. Relative to other age groups, nationwide estimates of physical activity are among the lowest in midlife. Average weekly usage of fitness facilities in the U.S. is also well below recommended levels of physical activity. Moreover, within the first 6 months of initiating a structured exercise program, dropout rates are approximately 50 percent. ?Booster strategies? have mainly been implemented within exercise interventions to increase compliance to study protocols, and it has yet to be determined whether training at the onset of enrollment in an exercise program can reduce attrition and increase long-term adherence and engagement in physical activity with limited professional guidance. Evidence suggests that general cognitive training and training specific to exercise- related cognitive processing has the potential to increase self-efficacy and self-regulatory strategies, and ultimately, exercise behavior maintenance. In the last decade, active videogame (exergaming) interventions have been used with aging populations to make exercise more enjoyable and prepare the brain for action. Active videogames have been successfully delivered within center- and home-based interventions and have yielded positive effects on mobility, cognitive functioning, psychosocial outcomes, and physical activity behavior. The purpose of this double- blinded, randomized controlled study is to compare CORTEX (Cognitive Regulation Training and Exercise), a multi-faceted, general and exercise-specific cognitive training program? involving 20 hours of active and traditional computerized cognitive training, delivered via a training center and at home?to an attention-control condition involving health and wellness informational videos. More specifically, the cognitive training group will emphasize dual-task abilities, memory, visual-spatial processing, as well as self-as-exerciser priming and self- certainty training. We hypothesize that a month-long cognitive training program will enhance cognitive and related self-regulatory functioning and self-efficacy and in turn, increase exercise adherence and engagement within a 12-month aerobic and resistive exercise program at a local fitness facility. We also expect more positive improvements in cognitive and psychosocial functioning among participants in the CORTEX condition as compared to the Video Control condition immediately following the cognitive booster training, and across time.